英语一般过去时在什么情况下用did/什么情况下用were /was

were /was 分别是be动词are/am的过去式,后面接形容词做表语,获接名词做宾语.
were是复数形式,主语只能用we,we were good,或 we were students.
was是单数形式,主语只能用I,I was good,或 I was a student.
did是动词do的过去是,主语可以是单数也可以是复数,you,he/she,they,it等都可以做主语
they did well,副词well 可以用来修饰did
they did a good thing,后面可以接名词.